Is it permissible for a man to marry his paternal uncle's daughter if his sister breastfed his paternal uncle's daughter along with her son?

Suckling makes unlawful what lineage makes unlawful. Thus, whoever suckles from a woman becomes her son through suckling. If your sister suckled your paternal uncle's daughter, then it is not permissible for you to marry her, because she has become your sister's daughter through suckling. It is a condition for prohibition that there be five full sucklings.